// 背景遮罩
.mask
  width: 100%;
  height: 100%;
  overflow: hidden;
  position: absolute;
  left: 0;
  top: 0;
  z-index: 10;
  .cover
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    z-index: 2;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    filter: blur(1.2rem);
    -webkit-filter: blur(1.2rem);
    -webkit-transform: scale(1.05);
  .cover-mask
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    z-index: 11;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,.8);

